We've got a rather big vote on Scottish independence going down Thursday, and the vote looks to be rather close. The No side seems to have a slight lead, but well within the margin for error.
While British PM Cameron has been up in Scotland trying to rally the "Better Together" No forces, the Tories are not all that popular in Scotland (their plurality in Parliament would be a majority were it not for a left-leaning Scottish caucus), so Scottish Labour politicians are fronting the No side.
The Scottish National Party heads up their regional government; one could make a loose analogy to the PQ in Quebec, as both pro-independence parties are to the left of their federal governments. Scotland would have custody of the UK's North Sea oil fields, which, if well managed, would (in theory) allow Scotland to have a more expansive government without paying through the nose in taxes.
In theory. Oil wealth doesn't always mean national wealth, as Venezuela shows us; Chavismo has squandered their oil wealth and screwed up their economy with nationalizations and bullying. The prospect of a socialist-inclined SNP nationalizing everything but the recipe for haggis helps to drive the No vote.
What could be interesting is that a simple majority would trigger a move to independence. If the vote is recount-close, would the loser accept a loss? Would a 50.1% Yes vote have a mandate to undo 300 years of ties?
You have a number of issues in play, like whether Scotland would be accepted in the EU (most likely, although Spain might want to veto to avoid a precident for its Catalonian minority) and whether Scotland would still use the British pound (a formal currency union would need to be approved by the remnant British government, but Scotland could use the pound without British permission like Panama uses the US dollar) and all the divorce logistics like where the UK's nuclear subs will light since their base is in Scotland and the SNP is anti-nuke.
If the Yes vote prevails, we have an interesting precedent for Spain, Canada, Ukraine and any number of other countries with restless minority sections.